If you are feeling really brave and have a certian degree of mechanical aptitude, try removing the woofer driver from the box, then glue a clean tin can on to the magnet structure(The magnet itself, not the basket). Tuna cans work well for this. Warning, before you break out the screwdriver, understand that it may void the manufacture warranty. You may want to do this to the tweeter magnet structure too. Good luck and happy listening!!

there are special mu metal cups available from zalytron in long island that are put over the magnet or attached to the rear of the cabinet behind the magnet. they work sometimes. not expensive. Mu metal shielding is available but you don't want to know the price. Lee